🦀 de_env

Deserialize environment variables through serde.

You may be looking for:

• API Documentation
• Crates.io

Example

Assuming we have a LOG and PORT environment variable:

#[derive(serde::Deserialize, Debug)]
#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
struct Config {
    log: String,
    port: u16
}

let config: Config = de_env::from_env().unwrap();

println!("{config:#?}");

Primitives

Strings & chars

The input is checked for UTF-8 validity and returned as is.

Numbers

If the input is valid Unicode, integers and floats are parsed with their respective FromStr implementations.

Booleans

Boolean parsing is case-insensitive.

If the truthy-falsy feature is enabled (default):

• Truthy values:
  • true or its shorthand t
  • yes or its shorthand y
  • on
  • 1
• Falsy values:
  • false or its shorthand f
  • no or its shorthand n
  • off
  • 0

If the truthy-falsy feature is disabled, only true and false are considered valid booleans.

Enums

Only unit variants can be deserialized.

Assuming we have a LEVEL environment variable set to HIGH, MEDIUM or LOW:

#[derive(serde::Deserialize, Debug)]
#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
enum Level {
    High,
    Medium,
    Low
}

#[derive(serde::Deserialize, Debug)]
#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
struct Pool {
    level: Level,
}

let pool: Pool = de_env::from_env().unwrap();

println!("{pool:#?}");

Unsupported types

• Nested structs
• Nested enums
• Nested maps
• Non-unit enum variants
• Tuples
• Sequences
• Byte Arrays